How many diseases can a tube of erythromycin eye ointment, which costs only a few dollars, cure?

Speaking of erythromycin eye ointment , I believe everyone is familiar with it. In some people's minds, such a small ointment of a few dollars is a "universal magic medicine". Although it is called eye ointment, it seems that it can also treat some minor problems in other parts of the body, such as inflammation of the corners of the mouth, acne, dry nose, etc.

Many people are wondering what kind of medicine is erythromycin eye ointment? Does it really have so many functions? What is the difference between it and erythromycin ointment? Are there any contraindications? Next, let's explain it to you clearly.

What is erythromycin eye ointment?

Erythromycin is an antibacterial drug belonging to the macrolide class. It exerts its antibacterial effect by inhibiting the synthesis of bacterial proteins and has antibacterial activity against Gram-positive bacteria, anaerobic bacteria, mycoplasma and chlamydia. Its main ingredients are erythromycin, liquid paraffin, lanolin and vaseline.
As a commonly used over-the-counter drug in ophthalmology, erythromycin eye ointment is mainly used for trachoma, conjunctivitis, blepharitis and external eye infections . In addition to ophthalmological related diseases, it can also be used for local infections such as bacterial external otitis and nasal vestibulitis .

Clinically, erythromycin eye ointment can be used for ophthalmic surgery (to prevent infection); nosebleeds (to stop bleeding), vestibulitis ; angular cheilitis (used in combination with vitamin B); skin diseases such as herpes and pressure sores ; anal inflammatory diseases of the anal canal, anal fissures and other anal-related diseases.

What is the difference between erythromycin ointment and erythromycin eye ointment?

Although there is only one letter difference between erythromycin ointment and erythromycin eye ointment, there are many differences in their usage and efficacy.

1) Different indications

Erythromycin ointment is a commonly used over-the-counter drug in dermatology , and is applicable to suppurative skin diseases such as impetigo, small-area burns, infections of ulcer surfaces, and acne vulgaris, that is, it is mainly used for skin injuries and minor infections of varying degrees. In addition, erythromycin ointment is also used to stop nosebleeds, and is used in combination with vitamin B2 to treat bacterial angular cheilitis, etc. As mentioned above, erythromycin eye ointment is a commonly used over-the-counter drug in ophthalmology, and is mainly used for eye-related diseases such as trachoma, conjunctivitis, blepharitis, and external eye infections, and local infections such as bacterial external otitis and nasal vestibulitis.

2) Different concentrations of the main ingredient, erythromycin

Although both contain erythromycin as their main ingredient, the amount of erythromycin they contain is different. The concentration of erythromycin in erythromycin ointment is 1%, while the concentration of erythromycin eye ointment is 0.5%. **If misused, erythromycin eye ointment may not achieve the therapeutic concentration required to fight skin infections.

3) Different degrees of sterility

During the production process of these two preparations, the preparation process of erythromycin eye ointment requires aseptic operation, while the preparation process of erythromycin ointment does not require aseptic operation .

4) Different particle sizes/irritation

During the preparation process, erythromycin eye ointment is required to be prepared into an extremely fine powder with very small particles, which should not be irritating to the eyes.

Erythromycin ointment has relatively loose requirements for particles, and only needs to be uniform and fine, with appropriate viscosity, easy to apply on the skin and non-irritating. Therefore, do not use erythromycin ointment for eye infections.

In what cases is erythromycin eye ointment not used?

Referring to the precautions for the use of macrolide drugs in the "Guidelines for the Clinical Application of Antimicrobial Drugs (2015 Edition)", the following points should be noted when using erythromycin eye ointment:

It should not be used by patients who are allergic to erythromycin or other macrolides.

Erythromycin should not be used in combination with terfenadine to avoid adverse cardiac reactions.

Patients with impaired liver function should reduce the dosage appropriately and have their liver function checked regularly if indicated.

In addition, erythromycin is also an antibiotic. When using any antibiotic, you should always keep in mind the concept of "rational use" and consult a doctor or clinical pharmacist before use. In addition, you should pay attention to the use cycle. Even if the condition improves, you should take the medicine according to the complete prescription, but you cannot use it for a long time. Overuse and abuse can cause bacterial resistance. If bacteria are resistant to all antibiotics, we will enter the post-antibiotic era and face the dilemma of no drugs available. By then, common infections and minor injuries will have the risk of death.

Expert of this article: Li Xue, PhD in Medicine, Peking Union Medical College